Deep Residential Retrofits in East Tennessee

Abstract

Executive Summary Oak Ridge National Laboratory (ORNL) is furthering residential energy retrofit research in the mixed-humid climate of East Tennessee by selecting 10 homes and guiding the homeowners in the energy retrofit process. The homeowners pay for the retrofits, and ORNL advises which retrofits to complete and collects post-retrofit data. This effort is in accordance with the Department of Energy s Building America program research goal of demonstrating market-ready energy retrofit packages that reduce home energy use by 30 50%. Through this research, ORNL researchers hope to understand why homeowners decide to partake in energy retrofits, the payback of home energy retrofits, and which retrofit packages most economically reduce energy use. Homeowner interviews help the researchers understand the homeowners experience. Information gathered during the interviews will aid in extending market penetration of home energy retrofits by helping researchers and the retrofit industry understand what drives homeowners in making positive decisions regarding these retrofits. This report summarizes the selection process, the pre-retrofit condition, the recommended retrofits, the actual cost of the retrofits (when available), and an estimated energy savings of the retrofit package using EnergyGauge . Of the 10 households selected to participate in the study, only five completed the recommendedmore » retrofits, three completed at least one but no more than three of the recommended retrofits, and two households did not complete any of the recommended retrofits. In the case of the two homes that did none of the recommended work, the pre-retrofit condition of the homes and the recommended retrofits are reported. The five homes that completed the recommended retrofits are monitored for energy consumption of the whole house, appliances, space conditioning equipment, water heater, and most of the other circuits with miscellaneous electric loads (MELs) and lighting. Thermal comfort is also monitored, with temperature and humidity measured in all conditioned zones, attics, crawlspaces, and unconditioned basements. In some homes, heat flux transducers are installed on the basement walls to help determine the insulating qualities of the technologies and practices. EnergyGauge is used to estimate the pre-retrofit and post-retrofit home energy rating system (HERS) index and reduction in energy consumption and energy bill. In a follow-up report, data from the installed sensors will be presented and analyzed as well as a comparison of the post-retrofit energy consumption of the home to the EnergyGauge model of the post-retrofit home. Table ES1 shows the retrofits that were completed at the eight households where some or all of the recommended retrofits were completed. Home aliases are used to keep the homeowners anonymous. Some key findings of this study thus far are listed as follows. Some homeowners (50%) are not willing to spend the money to reach 30 50% energy savings. Quality of retrofit work is significantly variable among contractors which impact the potential energy savings of the retrofit. Challenges exist in defining house volume and floor area. Of the five homes that completed all the recommended retrofits, energy bill savings was not the main driver for energy retrofits. In no case were the retrofits cost neutral given a 15 year loan at 7% interest for the retrofit costs.« less